Microwave Assisted Synthesis of Some Pyridine Derivatives Containing Mercaptotriazole and Thiazolidinone as a New Class of Antimicrobial Agents
摘要:
A fast and facile procedure for the synthesis of pyridomereaptotriazole 4a-e and pyridothiazolidinone 5a-e is being reported starting from diliydropyridine 1a-e. Subsequent oxidation with nitrating mixture (HNO3/H2SO4) produced the anticipated 2,6-dimethylpyridine derivatives 2a-e, which were subsequently condensed with thiosemicarbazide in ethanol to produce the key intermediate 2,2'-[4(4-substituted phenyl)- 2,6-dimethylpyridine-3,5-diyl]dicarbonyldihydrazine carbothioamides 3a-e. In the final step pyridomercaptotriazole derivatives 4a-e were synthesized by treating 3a-e in alkaline media. In parallel pyridothiazolidinone derivatives 5a-e were obtained by the reaction of 3a-e with ClCH2COOH/CH3COONa. All the reactions were carried out on microwave irradiation in good yield with short time. The structures of all the compounds have been confirmed on the basis of their analytical, IR, H-1 NMR, and Mass spectral data (Tables I and II). The potent antimicrobial effects of the synthesized compounds were also investigated.
In this article, efficient and simple preparation of Hantzschpyridine derivatives by reaction of various aldehydes and β-dicarbonyls in the presence of ammonium chlorate under solvent-free condition at 80°C is reported. The advantages of this system are the one-step procedure, high yields of the products, and the ability to carry out large-scale reactions. J. Heterocyclic Chem., (2009).
Reactivity of 1,4-Dihydropyridines toward Alkyl, Alkylperoxyl Radicals, and ABTS Radical Cation
作者:C. López-Alarcón、P. Navarrete、C. Camargo、J. A. Squella、L. J. Núñez-Vergara
DOI:10.1021/tx025579o
日期:2003.2.1
tested for potential scavenger effects towardalkyl, alkylperoxyl radicals, and ABTS radical cation in aqueous media at pH 7.4. Kinetic rate constants were assessed either by UV/vis spectroscopy or GC/MS techniques. Tested compounds reacted faster toward alkylperoxyl radicals and ABTS radical cation than alkyl ones. N-Ethyl-substituted DHPs showed the lowest reactivity. Kinetic results were compared with
Mannich reaction of dihydropyridine derivatives I. Reactions with secondary amines.
作者:JIRO ARITOMI、SHOZO UEDA、HARUKI NISHIMURA
DOI:10.1248/cpb.28.3163
日期:——
Dialkyl 4-aryl-1, 4-dihydro-2, 6-dimethylpyridine-3, 5-dicarboxylates (III) were subjected to the Mannich reaction with excess paraformaldehyde and secondary amine hydrochloride in boiling ethanolic solution. When the compounds III were treated with a 5-to 7-fold molar excess of the aldehyde and amine salt, 2, 6-bis (2-disubstituted aminoethyl)-dihydropyridine derivatives (V) were obtained in good yields. On treatment with a 2- to 3-fold molar excess of the reactants, compounds III were converted to 2-(2-disubstituted aminoethyl)-6-methyldihydropyridine derivatives (IV) and V. When dioxane was used as a solvent with a 6-fold molar excess of the reactants, the tetrakis (dimethylaminomethyl) derivative (VII) was obtained.
This communication expresses aromatisation of 1,4-dihydropyridines to pyridine derivatives with the help of alumina supported benzimidazolium fluorochromate (BIFC) and quinolinium fluorochromate (QFC) as oxidants undersolvent-free microwave irradiation. Moderate to excellent yield (80-98%) of pyridine derivatives were achieved by this methodology.
An Efficient Transition-Metal-Chloride/Sodium-Nitrite/TEMPO Catalytic System for Aerobic Oxidative Aromatisation of Hantzsch 1,4-Dihydropyridines
作者:Bin-Hui Lou、Shu-Bin Chen、Jian Wang、Ying Chen、Jing-Hua Li
DOI:10.3184/174751913x13701832537930
日期:2013.7
A facile and efficient transition-metal-chloride/sodium-nitrite/TEMPO catalytic system for aerobic oxidative aromati-sation of Hantzsch 1,4-dihydropyridines in high yields under mild conditions is described.